1. Field of the Invention
The present invention relates, in general, to a tong apparatus for a radiation shielding facility and, more particularly, to a joint tong apparatus for a radiation shielding facility in which a bar having a predetermined length is provided with a handle and a tong, each of which functions as a joint, at opposite ends thereof, thereby allowing the at-will handling of radioactive material being moved to a desired position and state in the radiation shielding facility.
2. Description of the Related Art
Generally, there is in danger of radiation exposure when radioactive material, or when a vessel, bottle or the like in which the radioactive material is contained, is moved to a desired position and state in the facilities in which highly radioactive nuclear material is handled.
In order to move the radioactive material, or the vessel, bottle or the like in which the radioactive material is contained, to a desired position and state which is out of the danger zone of this radiation exposure, various apparatuses that can be controlled remotely are used in the radiation shielding facilities.
Meanwhile, the shielding facilities where the radioactive material is handled should be equipped with isolated facilities in order to shield radiation, and be essentially equipped with a remote control apparatus such as a joint tong apparatus that enables remote handling (as mentioned above) in order to handle the radioactive material in the shielding facilities.
A conventional joint tong apparatus installed in the radiation shielding facilities in order to handle the radioactive material, or the vessel, bottle or the like in which the radioactive material is contained, is installed in a hole formed in the wall (or partition) of the radiation shielding facilities, and includes a spherical member having a through-hole passing therethrough, and a pair of spherical shells located in the hole together with the spherical member so as to enclose the spherical member on diametrically opposite sides of the spherical member. Thus, the spherical member can freely carry out rotational motion in the pair of spherical shells.
The conventional joint tong apparatus further includes a long bar that is inserted and coupled into and to the through-hole of the spherical member and which can make longitudinal motion and rotational motion with respect to the spherical member, a handle and a tong mounted on respective opposite ends of the bar, and steel wires connecting the handle with the tong and manipulating the tong while passing through the inside of the bar. Thus, the radioactive material, or the vessel, bottle or the like in which the radioactive material is contained, can be handled at a remote position.
However, this conventional joint tong apparatus not only has a great difficulty in handling the radioactive material, or the vessel, bottle or the like in which the radioactive material is contained, in arbitrary directions and states because the handle and tong mounted on respective opposite ends of the bar are in a stationary state, but also makes it impossible to stop all motion of the radioactive material, or the vessel, bottle or the like in which the radioactive material is contained, at arbitrary positions and states during handling because it is not equipped with a locking apparatus for controlling the operation of the handle and tong, namely fixing the positions of the handle and tong.
Particularly, since the handle and tong are fixedly mounted on opposite ends of the bar, the radioactive material in a liquid state may leak out while the bar makes forward/backward and rotational motions with respect to the spherical member when being handled, which leads to a serious problem.